Heat treatment method and apparatus



Feb. 28, 1939. P. R. HOOPES HEAT TREATMENT METHOD AND APPARATUS OriginalFiled Feb. 19, 1934 Patented Feb. 28, 1939 g 2,148,859 HEAT TREATMENTAPPARA METHOD AND TUS Penrose It. Hoopcs, Philadelphia, Pa; assignor toThe Selas Company, Philadelphia, Pa., a corporation of PennsylvaniaApplication February 19, 1934, Serial No. 711,852

Renewed January 11, 1939 .10 Claims.

The general object of the present invention is to provide an improvedmethod of and apparatus for subjecting a traveling web of cloth, paper,or analogous material to a heating action in a localized portion of thepath of web travel, The embodiment of the invention illustrated anddescribed in detail herein was primarily devised for use insingeingcloth, but is well adapted for use in drying paper webs and printed websof paper or woven fabric, and in general, for subjecting such webmaterial to a heating action analogous to that required for the abovementioned singeing and drying purposes.

The invention in its preferred form is characterized by the longitudinalmovement of the web treated along a path including a loop portiondefined by guides including a guide bar at the crown of the loop aboutwhich the web is looped and from the opposite sides of which the webloop limbs extend under tension, and by the subjection of the web loopto a heating action due to the combustion of gas, and preferably acombustible mixture of air and gas, adjacent but at the convex or outerside of the web loop crown and including in addition to the directheating effect of the gas combustion, and the contact of the heating gaswith the web loop, a radiation of heat to the outer side of one, orpreferably both limbs of the web loop, from heat absorbing and radiatingrefractory material alongside of but spaced away from each limb to whichheat is so radiated. When, as is ordinarily preferable, heat is soradiated to each limb of the web loop, the heat absorbing and radiatingrefractory material forms the oppositely inclined sides of an open endedtrough like space which is formed in a heating element or burnerstructure, and in which the web loop is nested, so to speak. In thepreferred embodiment of the invention, the bottom wall of said troughshaped space is formed with burner channels or orifices opening to saidspace from a subjacent gas supply chamber, and the heating element wallsdefining said trough shaped space and the web loop limbs collectivelydefine a heating chamber which is V-shaped in cross section and fromwhich the gaseous products of combustion issue at the edges of saidchamber remote from its apex which extends longitudinally of the crownof the web loop.

More specific objects of the invention are to provide an apparatus foruse in the practice of the above described method characterized by itsmechanical and operating simplicity and effectiveness, and by featuresof construction and arrangement whereby the relative thermal expansionand contraction of its parts occurring under varying conditions ofoperation are accommodated, and by the features provided to accommodatethe ready introduction of a material web into the apparatus, and by thefeatures provided for the efficient handling of material webs of lesswidths than the maximum width which tion. I r

Fig. 2 is a section on the line 2-2 of Fig. 1; and Fig. 3 is a plan viewof a portion of the burner structure of the apparatus.

The apparatus shown in the drawing was pri marily devised and designedfor singeing a cloth web a, as the latter is moved rapidly through theapparatus by web feeding means which may be of any suitable characterandmay be independent of the singeing apparatus proper and hence need notbe illustrated herein, but the apparatus shown is adapted for use withlittle or no change in heating web material for drying and otherpurposes.

The stationary portions of the apparatus shown comprise vertical endframe members A connected by horizontal lower and upper cross framemembers or bars B and C, respectively, and a heating element including ametallic burner body member D longitudinally disposed between the endframe members A. As shown, the burner body D is formed with slidebracket extensions D which are notched to receive the cross frame bars Bby which the heating element is supported. The brackets D may slide onthe bars B longitudinally of the latter as required to accommodate therelative longitudinal expansion of the bars and burner body D as theirrelative temperatures vary. As shown, the end frame members A aremounted on supporting pedestals E.

2d subjecting a web to heat treatment, with parts of the apparatusbroken away and shown in sec f At its upper side the heating element isformed 7 with a trough shaped heating space extending longitudinally ofthe burner body D and open at its top and ends. The oppositely inclinedside walls of said space are formed by slab like bodies F of heatabsorbing refractory material of relatively low heat conductivity, suchas is commonly referred to as an insulating refractory material. Theinner inclined faces of the bodies F extend upward from a narrowhorizontal bottom wall G formed with vertically disposed burner orificesor channels G leading to the trough shaped heating space from asubjaoent burner gas supply chamber. The latter, as shown, is divided bytransverse web or division walls 1) into a series of end to endcompartments D and D whereby regulation of the distribution of heat tothe heating space longitudinally of the latter is facilitated, and thesupply of heat to the heating space may be restricted to such portion ofthe length of the latter as needs to be heated in handling a web of awidth less than that of the maximum width which can be handled in theapparatus. As shown, the supply chamber compartment D extends for abouta quarter of the length of the heating element at each side of thecenter of the latter, and there are four similar compartments D at eachend of the compartment D.

In the arrangement shown, the compartment D is supplied with gas, ofpreferably a. combustible mixture of air and gas, through two branches Hfrom a distributing pipe H alongside the heating element and receivinggas, or a combustible mixture of gas and air, from a suitable source,not illustrated. Each of the compartments D is connected to the pipeHthrough an individual branch pipe I-Iincluding a regulating and cut offvalve H As shown, the burner body D is formedwith an end to end seriesof slots or openings D at the upper sides of the compartments D and Dthrough which gas may pass from the latter into the lower ends ofcorresponding orifices or burner channels G in the wall G, there beingone slot for each of the compartments D and a plurality of such slots,separated by grid or tie bars D, for the compartment D The use of thelatter facilitates the forma-' tion of, and gives additional strength tothe burner body casting. Each division wall D and grid bar D has itsupper portion beveled off to form a sharp corner edge engaging the underside of the wall G, so that it need obstruct flow through none of thechannels G which are suitably distributed to avoid any tendency tostreaky action of the flame jets on the web of material treated. withall of the compartments D and D receiving gas, the channels G aresupplied with gas as they would be if the end to end slots D werereplaced by a single long slot.

As shown the wall G extends across the aligned slots D and has edgeportions suitably secured as by means of clamping plates G against seatportions of the burner body D at the sides of said slots. The refractoryslabs F are shown as disposed with their lower portions alongside of, orin overlapping relation with an upper portion of the wall G and aresupported by engagement with the clamping plates Cl and suitably shapedportions of the burner body D, which comprises upper inclined portionsD" at the outer sides of the body F to the upper edges of which platesare detachably secured to clamp the bodies F in place.

In the normal operative. condition of the :apparatus shown in Fig. 2,the web a is looped about a guide bar I which extends into the troughshaped space between the bodies F and above the wall G. As shown, theguide bar I is of T-bar cross section, with its head flanges uppermost.The lower edge I of the web or stem portion of the bar I defines andpositions the crown of the web loop, and is smooth and rounded tofacilitate the movement of the web over it. The two limbs of the webloop extend in normal operation under tension from the opposite sides ofthe edges I and in substantial parallelism with the respectivelyadjacent faces of the refractory bodies F to web guiding members whichmight be in the form of rollers, but as shown are formed by thenon-rotatable cross frame members C. The latter are round and smooth tofacilitate the movement of the web over them. As shown,- the outer edgesI of the head flanges of the bar I are smooth and rounded and normallyin position to contact with the limbs of the web loop extending betweenthe bar edge I and the web guides formed by the bars C.

In the operative condition of the apparatus illustrated in Fig. 2, thebodies F, wall G and the limbs of the web loop extending about the guidebar edge I form the walls of a heating chamber d which extendslongitudinally of the burner body D for the full width of the web a, andwhich is V shaped in cross section, and which is .open to the atmosphereat its ends and at its upper edges which are at the level of the tops ofthe refractory bodies F. To permit of adjustment in the thickness of thechamber d, and particularly of the portion of the latter between thecrown of the web loop and the plate G, provisions are advantageouslymade for the vertical adjustment of the guide bar I. In the constructionshown,

a the vertical adjustment provisions for the bar I are adapted to movethe latter from the operative position shown in Fig. 2, into theinoperative position shown in Fig. 1, wherein the edge I' of the bar Iis well above the level of the tops of the bars 0. The relativepositions of the bars C and I shown in Fig. 1, facilitates the initialintroduction of the web into the apparatus. I With the web a extendinghorizontally between the bars 0 as it may with the apparatus adjusted asshown in Fig. 1, all risk of injuriously heating the web while it isbeing introduced into the apparatus, or when the web travel isinterrupted for any cause is avoided.

The means shown for supporting the guide bar I and giving the latter itsvertical adjustments comprise a supporting bar J directly above the barI and shown as in the form of an I-beam, from which the guide bar I issuspended by bolts J distributed along the length of the beam andextending through openings in the bottom flange of the latter and in thehead flanges of the bar I. Provisions are advantageously made, as by asuitable enlargement of said openings, to permit longitudinal thermalexpansion and contraction of the bar I relative to ,the beam J. The barI should be made of metal adapted to withstand the considerabletemperatures to which it is subjected in operation. To suitably minimizeany tendency of the bar I to warp as a result of thermal stresses towhich it is subjected, and to minimize the transfer of heat byconduction from its bottom edge I to its head, and the consequenttransfer of heat from the bar I to the beam J,

a multiplicity of large openings F are advantageously formed in the webor .stem portion of the bar I.

The means shown for vertically adjusting the passage through whichextends the threaded portion of a corresponding adjusting and supportingshaft L journalled in the correspondin end frame member A, and movablerotatably, but not axially, relative to the latter. At its lower endeach shaft L carries a beveled gear L, meshing with a correspondingbeveled gear M secured to a horizontal shaft M below the burner body Dand suitably journalled in the end frame member A. The shaft M may berotated as required to raise and lower the threaded members K andthereby the beam J and guide bar I manually or by any suitable powermechanism. As shown, the shaft M is provided at one end with a handwheel M for the manual rotation of the shaft. Advantageously the membersK are guided in their vertical movements by the engagement of suitablyshaped guiding surfaces of those members with guideways A formed for thepurpose in the end frame members A, and the connections K between themembers K and the ends of the beam 3 are adapted to permit of somelongitudinal expansion and contraction of the beam J withoutcorresponding movements of separation and approach of the two members K.

In the contemplated mode of use of the apparatus, the latter is adjustedinto the general position shown in Fig. 2 and heat is supplied by theheating element, and the web a is advanced at respective rates suitablefor the particular condition of operation. The form of the apparatus andits contemplated mode of use permit of a rate of web feed substantiallyhigher than has heretofore been customary or is practically possiblewith previously known web singeing machines.

For any web heat treating operation, it is in general essential that theeffective heating action on the web should be augmented and diminishedas the speed of web travel is increased and diminished. With theapparatus disclosed, the intensity of the heating eifect impressed onthe web may be varied by varying the composition or pressure of the gasor air gas mixture supplied to the compartments l3 and D and may also bevaried somewhat by adjustment of the guide bar I toward and away fromthe heating element. The heating action due to combustion, which occursmainly in the space between the crown of the web loop and the wall G,and due to contact of the heating gases with the web loop,.issupplemented to a substantial degree in the arrangement shown, by heatradiated against the extended web loop limbs from the extended heatabsorbing and radiating inner faces of the bodies F.

In singeing cloth the effectiveness of the singeing operation isaugmented by the opening of the woven fabric as the latter bends sharplyabout the edge I of the guide bar I. This bending of the web when undersuitable tension tends to move the loose ends of fibers away from theouter side of the web and toward the adjacent portions of the heatingelement. When it is desirable to singe both sides of a cloth, web, thatresult may be secured by passing the web in series through two singeingdevices of the kind shown in such fashion that one device operated onone side, and the other on the opposite side of the web, or the web maybe passed twice through the single device shown so as to singe one sideduring one passage, and to singe the other side during the secondpassage of the web through the apparatus. The movement of the web undertension over the edges 1' and P of the guide bar I, and particularlyover the more highly heated edges 1' subjects the web to a desirableironing action.

For many uses it is convenient to dispose the heating elementhorizontally and so that the web loop extends downward into the spacebetween the refractory block bodies F as illustrated, but, as will beapparent, this disposition of the parts may be altered as conditionsmake desirable. The essential operating characteristics of the apparatusshown would not be modified by adjustment of the apparatus to bring itsheating element into vertical or inclined position, or to bring theguide bars C below the level of the heating element.

While in accordance with the provisions of the statutes, I haveillustrated and described the best form of embodiment of my inventionnow known to me, it will be apparent to those skilled in the art thatchanges may be in the form of the apparatus disclosed without departingfrom the spirit of my invention as set forth in the appended claims andthat in some cases certain features of my invention may be used toadvantage without a corresponding use of other features.

Having now described my invention, what I claim as new and desire tosecure by Letters Patent is:

1. Apparatus for subjecting a traveling web to a localized heatingeffect, comprising a heating element formed with a trough shaped space,and relatively cool guiding means separate from and out of contact-withsaid heating element for causing the web treated to move along a pathincluding a loop portion extending into said space with the crown of theweb loop parallel and adjacent to but spaced away from the bottom ofsaid space and with the limbs of the web loop alongside and spaced awayfrom the.

side walls of said loop, said heating element comprising fuel burnerorifices opening to said space adjacent the bottom of the latter, andcomprising portions forming the side walls of said space consisting ofrefractory material of relatively poor heat conductivity. 5

2. Apparatus for subjecting a traveling web to a localized heatingeffect, comprising a heating element formed with a trough shaped space,relatively cool guiding means separate from and out of contact with saidheating element for causing the web treated to move along a pathincluding a loop portion extending into said space with the crown of theweb loop parallel and adjacent to but spaced away from the botloopalongside and spaced away from the side walls of said loop, and meansfor burning a combustible gaseous mixture into the portion of said spaceat the outer side of the web loop, said element comprising portionsforming the side walls of said space consisting of refractory materialof relatively poor heat conductivity.

3. Apparatus for subjecting a traveling web to a localized heatingeffect comprising a heating element formed with a trough shaped heatingspace, guiding means for causing the web treated to move along a pathincluding a loop portion extending into said space with the crown of theweb loop parallel and adjacent to the bottom of said space, said guidingmeans comprising a guiding bar movable toward and away from the bottomof said space between positions within and without the latter, andcooperating guiding members a localized heating eflect comprising aheating element formed with a trough shaped heating space, guiding meansfor causing the web treated to move along a path including a loopportion extending into said space with the crown of the web loopparallel and adjacent to the bottom of said space, said guiding meanscomprising a guiding bar movable toward and away from the bottom of saidspace between positions within and without the latter and cooperatingmembers outside of said space and between which said guiding bar passesin moving between said positions.

5. Apparatus for subjecting a traveling web to a localized heatingefiect comprising a heating element formed with a trough shaped space,and web relatively cool guiding means for causing the web treated tomove along a path out of contact with said element and including a loopportion extending into space with the crown of the web loop parallel andadjacent to but spaced away from the bottom of said space and with thelimbs of the web loop alongside and spaced away from the side walls ofsaid space, and means for generating combustion heat within the portionof said space between the bottom of the latter and the crown of the web,the portions of said element forming the side walls of said space beingformed of refractory material of poor heat conductivity.

6. Apparatus for subjecting a traveling web to a localized heatingeffect, comprising a heating element formed with a trough shaped heatingspace, and guiding means for causing the web treated to move along apath including a loop portion extending into said space with the crownof the web loop parallel and adjacent to, but spaced away from thebottom of said space, and including a guide bar having a portiondefining said web crown, said bar being cut away to minimize heatconduction and the tendency of said bar to warp under thermal stresses.

'7. Apparatus for subjecting a traveling web to a localized heatingeifect, comprising a heating element formed with a trough shaped heatingspace, guiding means for causing the web treated to move along a pathincluding a loop portion extending into said space with the crown of theweb loop parallel and adjacent to, .but spaced away from the bottom ofsaid space, and including a guide bar about which said loop extends anden- 8. Apparatus for subjecting a traveling web to a localized heatingeffect comprising a framework including spaced apart end frame members,a heating element supported by said framework and longitudinallydisposed between said end frames and formed with a trough shaped spaceweb, guiding means for causing the web treated to move along a pathincluding a loop portion extending into said space with the crown of theweb loop parallel and adjacent to the bottom of said space, said guidingmeans comprising a guide bar, means mounted in said end frames formoving said bar toward and away from the bottom of said space betweenpositions, respectively, within and out of said space, and cross framemembers at the opposite sides of the path of movement of said guidingbar forming web guides between' which and said bar the limbs of saidloop extend when said bar is within said space, and between which saidweb may extend without flexure when said bar is in a position out ofsaid space.

9. In apparatus of the character described, a

heating element comprising an elongated gas supply chamber and a wallportion at one side thereof formed of refractory material with burneroppositely inclined to form the side walls of a trough shaped combustionspace of which saidwall portion forms the bottom wall, and means forguiding a travelling web along a path including oppositely inclinedportions respectively adjacent said side walls and spaced away from thelatter and defining the side of said combustion space directly opposedto the side thereof formed by said side walls.

10. Apparatus for subjecting a travelling web to e said web and portionapart to substantially increasethe distance between them and therebysubstantially reduce the transmission of heat to the web from saidincandescent refractory material. 3

PENROSE R. HOOPES.

